<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<script>
  Function.prototype.addMethod = function (name, fn) {
    this[name] = fn;
  }
  var methods = new Function();
  methods.addMethod('checkName', function(){
    // 验证姓名
    console.log('name checked');
    return this;
  });
  methods.addMethod('checkEmail', function(){
    // 验证邮箱
    console.log('email checked')
    return this;
  });
  methods.addMethod('checkPassword', function(){
    //验证密码
    console.log('password checked');
    return this;
  });

  methods.checkName().checkEmail().checkPassword()



</script>
</body>
</html>